The trash compactor

[Rihanna]

Sex Position: When in the missionary position, [the gentleman] sits back on his knees, grabs the two legs of the lady, and brings them vertically together, as if she looks to be in a L position. Then, he pushes the legs back, to where her knees are about touching her chest. At this point, the green [light is on], and the [trash compactor] is initiated.